Metal compound particle group, electrode for power storage device, power storage device, and method for producing metal compound particle group

Abstract

A metal compound particle group that can suppress increase of internal resistance of power storage device, an electrode including the metal compound particle group for power storage device, and a method for producing the metal compound particle group are provided. A metal compound particle group has a 3D network structure in which metal compound particles are linked, and a coating layer C including silicon oxide is formed on a part of the metal compound particle group. The coating layer C including silicon oxide is formed on at least a part of a surface of the metal compound particle group. A gap 2 exists in the 3D network structure, and the coating layer C including silicon oxide is formed on the surface of the metal compound particle defining the gap 2 . The coating layer C including silicon oxide is an amorphous silicon oxide.

1 . A metal compound particle group having a 3D network structure in which metal compound particles are linked, the metal compound particle group comprising:
 a coating layer including silicon oxide is formed on a part of the metal compound particle group.   
     
     
         2 . The metal compound particle group according to  claim 1 , wherein the coating layer including silicon oxide is formed on at least a part of a surface of the metal compound particle group. 
     
     
         3 . The metal compound particle group according to  claim 1 , wherein Si element is included in an amount of 0.4 wt % or more and 3.0 wt % or less relative to all metal compound particle group. 
     
     
         4 . The metal compound particle group according to  claim 1 , wherein:
 a gap exists in the 3D network structure, and   the coating layer including silicon oxide is formed on the surface of the metal compound particle defining the gap.   
     
     
         5 . The metal compound particle group according to  claim 1 , wherein the coating layer including silicon oxide is an amorphous silicon oxide. 
     
     
         6 . The metal compound particle group according to  claim 1 , wherein a pore volume change rate calculated from a pore distribution of the metal compound particle group measured by a nitrogen gas adsorption measurement method is more than 0.008 dV p /dr p  relative to the pore diameter of 10 nm or less. 
     
     
         7 . The metal compound particle group according to  claim 1 , wherein a reduction rate of an integrated intensity is 25% or more relative to the metal compound particle group on which the coating layer including silicon oxide is not formed. 
     
     
         8 . The metal compound particle group according to  claim 1 , wherein the metal compound particle is lithium titanate. 
     
     
         9 . An electrode for a power storage device including the metal compound particle group according to  claim 1 . 
     
     
         10 . The power storage device comprising:
 an element which including a negative electrode that is the electrode for the power storage device according to  claim 9 , and a positive electrode; and   an electrolytic solution impregnated in the element,   wherein the electrolytic solution includes a fluorine-containing compound.   
     
     
         11 . A method for producing the metal compound particle group comprising:
 a mixing process of mixing the metal compound particle group that is a basis and a source material of silicon oxide, and   a heating process of heating a powder obtained by the mixing process at a temperature of 300° C. to 600° C.   
     
     
         12 . The method for producing the metal compound particle group according to  claim 11 , wherein the source material of silicon oxide is mixed in a ratio of 1 wt % to 20 wt % relative to a weight of the metal compound particle group that is the basis. 
     
     
         13 . The method for producing the metal compound particle group according to  claim 12 , wherein the source material of silicon oxide is mixed in a ratio of 3 wt % to 20 wt % relative to a weight of the metal compound particle group that is the basis. 
     
     
         14 . The method for producing the metal compound particle group according to  claim 11 , wherein in the mixing process, one type or two types or more alkaline compound is mixed. 
     
     
         15 . The method for producing the metal compound particle group according to  claim 11 , further comprising, before the mixing process, a pre-processing process of pre-processing the metal compound particle group that is the basis with alkaline compound. 
     
     
         16 . The method for producing the metal compound particle group according to  claim 14 , wherein the alkaline compound is hydroxide, acetate, sulfate, carbonate, nitrate, and chloride of alkali metal or alkali earth metal, and inorganic alkaline agent or organic alkaline agent. 
     
     
         17 . The metal compound particle group according to  claim 3 , wherein:
 a gap exists in the 3D network structure, and   the coating layer including silicon oxide is formed on the surface of the metal compound particle defining the gap.   
     
     
         18 . The metal compound particle group according to  claim 3 , wherein the coating layer including silicon oxide is an amorphous silicon oxide. 
     
     
         19 . The metal compound particle group according to  claim 3 , wherein a pore volume change rate calculated from a pore distribution of the metal compound particle group measured by a nitrogen gas adsorption measurement method is more than 0.008 dV p /dr p  relative to the pore diameter of 10 nm or less. 
     
     
         20 . The metal compound particle group according to  claim 3 , wherein a reduction rate of an integrated intensity is 25% or more relative to the metal compound particle group on which the coating layer including silicon oxide is not formed.